Impact of new International Association of Diabetes and Pregnancy Study Groups (IADPSG) diagnostic criteria on perinatal outcomes in a regional tertiary hospital in New South Wales, Australia

Aims: We compared the impact of new gestational diabetes (GDM) diagnostic criteria by IADPSG with previous criteria to ascertain concordance between the two criteria; and whether women discordant for GDM between the old and new criteria had increased pregnancy complications.

Methods: Oral glucose tolerance tests of pregnant women across time periods using old criteria and new criteria were collected. Maternal data and perinatal outcomes were compared between diagnostic concordant and discordant women.

Results: In total, 666/5178 (12.9%) women were diagnosed and treated for GDM. There was a significant increase in odds of any complication in concordant positive women (OR 3.91 95%CI 2.71-5.63, p<.0001); in women only positive by new GDM criteria (OR 2.06, 95% CI 1.41-2.99, p=.0002); and women only positive by old GDM criteria (OR 2.28, 95% CI 1.42-3.66, p=.0006); compared to concordant negative women. This is mainly due to macrosomia and nursery admissions.

Conclusion: This study confirms that women diagnosed with GDM on both old and new criteria have a higher rate of birth complications than women without GDM. Women who have been missed out due to new criteria may still be at risk. Therefore, combination of both old and new criteria may be optimal for identifying high-risk pregnancies.